Effect of partial root-zone drying irrigation and plant density on yield and water productivity of forage corn

To study the effect of different methods of partial root-zone drying irrigation and plant density on yield and water productivity of forage corn a field experiment was carried out in split plot arrangement using randomized complete block design with four replications at soil and water research institute, Karaj, Iran in 2014-2015 growing year. Different irrigation methods in three levels: I1: conventional furrow irrigation, I2: intermittent alternate furrow irrigation, I3: the fixed alternate furrow irrigation that were located in the main plots and plant density in three levels: D1: 75000 plants per hectare, D2: density of 85,000 per hectare, D3: density of 95,000 plants per hectare that were located in the sub plots. Results showed that the highest water productivity of Grain yield was achieved in treatment of the intermittent alternate furrow irrigation which showed 21.6 % significant increase in comparison to conventional furrow irrigation. Generally, method of intermittent alternate partial irrigation was a significant advantage compared to other irrigation methods in order to increase water productivity. The highest water productivity for biological fresh yield (11.97 kg.m-3) and WP for biological dry yield (3.91 kg.m-3) was achieved in treatment of the intermittent alternate furrow irrigation and density of 85,000 plant per hectare that increased 27.2% and 31.2% as compared to control treatment, respectively. Thus, method of partial root-zone drying irrigation (intermittent alternate) and density of 85,000 plants per hectare to increase productivity of forage corn is suggested in Karaj area.